Civil and mechanical engineering projects, GIS (Geographical Information Systems) mapping programs, military simulations, and numerous other applications all require accurate three dimensional (3D) computer models of real-world objects.
Most previous methods for creating 3D models involve extensive manual measurement and modeling. The measuring component may be achieved either through direct measurement (such as surveying) of the objects themselves or through measuring images of the objects using the science of photogrammetry. The modeling component typically involves manually inputting the measurements into computer modeling programs such as computer-aided design (CAD) software, GIS, or other similar solid modeling packages. This process is labor intensive and error prone.
Point cloud capture technology, such as laser scanning or automated photogrammetric stereo matching, is a relatively new technology for improving upon this 3D-modeling process. These systems scan objects or scenes to construct a “point cloud” consisting of many 3D point measurements of the scene. These points can then be used to guide the process of feature extraction.
Many companies need virtual 3D models of their industrial facilities, and it has become accepted practice to scan these facilities and create these virtual 3D models using the resulting point cloud data. Structural steel and other extruded shapes such as ducting, piping, and cable trays represent some of the most commonly modeled shapes. Unfortunately, modeling these types of items and accurately fitting them to the point cloud is very tedious with traditional CAD software.